The concept of Prakruthi, and its varied aspects have been described in detail in the following classical texts of Ayurveda in the sections given. In each case we have referred to a standard edition of the text with its English/Hindi Translation.

Sankhya and Yoga form as it were the twin providing the conceptual foundation for the philosophical basis for Indian Medicine. The basic source book for Sankhya is the "Sankhya Karika" and the basic text of Yoga is the "Yoga Sutra" of Patanjali. We have listed below editions of these tow texts that provide an English translation of the texts with commentary.

The Bhagawad Gita is a very important source book of various schools of Indian thought. It enters into a detailed discussion of the three Gunas - Satva, Rajas and Tamas. There are a large number of edition and translations of the Gita and every important Achaarya has written a commentary. Discussion about the nature of Satva Rajas and Tamas are found in -

Chapter XIV the Yoga of the division of the three Gunas Chapter XVII The Yoga of the division of the three fold Faith Chapter XVIII The Yoga of liberation and renunciation.

IV. Scientific Basis of Ayurveda

Throughout this book we have employed the technical terminology of Ayurveda. The following two books provide an introduction of this area to the reader.

The Art and Science of Indian Medicine by G.Srinivasamurthy (Theosophical Publishing House, Madras), 1986, Reprint. Captain G.Srinivasamurthy was a modern medical practitioner who was the Member Secretary to the "Usman Committee" - a committee appointed by the Government of Madras Presidency in 1921 to enquire into the State of Indigenous Medical Practice. This book was first published as an Appendix to the Usman Committee Report.

Local Health Traditions: An Introduction by A.V Balasubramanian and M. Radhika (Lok Swasthya Parampara Samvardhan Samithi, Madras) 1989. The forth chapter deals with the "Scientific Basis of Indian Systems of Medicine".